From 8f17461bdfeed758f2be71529fc3af55a76ea3e1 Mon Sep 17 00:00:00 2001 From: Uros Bizjak Date: Mon, 18 May 2020 17:52:14 +0200 Subject: [PATCH] i386: Avoid reversing a non-trapping comparison to a trapping one [PR95169] gcc/ChangeLog: PR target/95169 * config/i386/i386-expand.c (ix86_expand_int_movcc): Avoid reversing a non-trapping comparison to a trapping one. testsuite/ChangeLog: PR target/95169 * gcc.target/i386/pr95169.c: New test. --- gcc/ChangeLog | 6 ++++++ gcc/config/i386/i386-expand.c | 27 +++++++++++++++--------- gcc/testsuite/ChangeLog | 6 ++++++ gcc/testsuite/gcc.target/i386/pr95169.c | 28 +++++++++++++++++++++++++ 4 files changed, 57 insertions(+), 10 deletions(-) create mode 100644 gcc/testsuite/gcc.target/i386/pr95169.c diff --git a/gcc/ChangeLog b/gcc/ChangeLog index dffe88fdcca..4082217fd35 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2020-05-18 Uroš Bizjak + + PR target/95169 + * config/i386/i386-expand.c (ix86_expand_int_movcc): + Avoid reversing a non-trapping comparison to a trapping one. + 2020-05-18 Alex Coplan * config/arm/arm.c (output_move_double): Fix codegen when loading into diff --git a/gcc/config/i386/i386-expand.c b/gcc/config/i386/i386-expand.c index 2865cced66c..79f827fd653 100644 --- a/gcc/config/i386/i386-expand.c +++ b/gcc/config/i386/i386-expand.c @@ -3057,11 +3057,14 @@ ix86_expand_int_movcc (rtx operands[]) { gcc_assert (!DECIMAL_FLOAT_MODE_P (cmp_mode)); - /* We may be reversing unordered compare to normal compare, that - is not valid in general (we may convert non-trapping condition - to trapping one), however on i386 we currently emit all - comparisons unordered. */ - new_code = reverse_condition_maybe_unordered (code); + /* We may be reversing a non-trapping + comparison to a trapping comparison. */ + if (HONOR_NANS (cmp_mode) && flag_trapping_math + && code != EQ && code != NE + && code != ORDERED && code != UNORDERED) + new_code = UNKNOWN; + else + new_code = reverse_condition_maybe_unordered (code); } else new_code = ix86_reverse_condition (code, cmp_mode); @@ -3213,11 +3216,15 @@ ix86_expand_int_movcc (rtx operands[]) { gcc_assert (!DECIMAL_FLOAT_MODE_P (cmp_mode)); - /* We may be reversing unordered compare to normal compare, - that is not valid in general (we may convert non-trapping - condition to trapping one), however on i386 we currently - emit all comparisons unordered. */ - new_code = reverse_condition_maybe_unordered (code); + /* We may be reversing a non-trapping + comparison to a trapping comparison. */ + if (HONOR_NANS (cmp_mode) && flag_trapping_math + && code != EQ && code != NE + && code != ORDERED && code != UNORDERED) + new_code = UNKNOWN; + else + new_code = reverse_condition_maybe_unordered (code); + } else { diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 89423f5dfb9..320095c49ae 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,4 +1,10 @@ +2020-05-18 Uroš Bizjak + + PR target/95169 + * gcc.target/i386/pr95169.c: New test. + 2020-05-18 Alex Coplan + * gcc.c-torture/compile/packed-aligned-1.c: New test. * gcc.c-torture/execute/packed-aligned.c: New test. diff --git a/gcc/testsuite/gcc.target/i386/pr95169.c b/gcc/testsuite/gcc.target/i386/pr95169.c new file mode 100644 index 00000000000..91411744228 --- /dev/null +++ b/gcc/testsuite/gcc.target/i386/pr95169.c @@ -0,0 +1,28 @@ +/* PR target/95169 */ +/* { dg-do run { target ia32 } } */ +/* { dg-options "-O0 -march=i386 -mtune=generic" } */ +/* { dg-require-effective-target fenv_exceptions } */ + +#include + +void +f (double y) +{ + if (__builtin_expect (y == 0.0, 0)) + __builtin_abort (); +} + +int +main (void) +{ + double y = __builtin_nan (""); + + feclearexcept (FE_INVALID); + + f (y); + + if (fetestexcept (FE_INVALID)) + __builtin_abort (); + + return 0; +} -- 2.30.2